This invention relates in general to hand tools and, in particular, to a safety chisel especially adapted to shear bolts having a nut permanently attached thereto, while retaining the sheared bolt and nut assembly within a safety container portion of the chisel.
In certain applications, such as securing a brake band onto a brake block, self-locking nuts are utilized on brake lock bolts to secure the brake band to the brake block, with the intention that the nuts will be permanently secured to the brake block bolts. Once these self-locking nuts are installed, they are not intended to be threadingly disengaged, but are constructed such that the installation is permanent. Until such time as the brake bands must be repaired, the brake block nut and bolt assembly forms an integral part.
In other instances, even where a nut and bolt assembly is secured without such a permanent assembly being intended, it is well known that through rust, corrosion, or other deterioration-inducing factors, nuts become impossible to be threadingly removed from the bolt upon which they were engaged. Under such circumstances, the bolt upon which the nut is secured, or the nut itself, must be cut or sheared so that the portion of the bolt remaining can then be knocked out of the hole and replaced.
Such a shearing operation, however, frequently results in the sheared portion of the nut and bolt assembly flying about in an unpredictable direction, which can cause injury to any personnel in the area or damage equipment with which it may impact or become entangled.
The present invention provides a safety chisel which permits a bolt to be sheared, while the nut and portion of the bolt to which the nut is affixed are entrapped and contained within a safety container. The safety container prevents the broken portion of the bolt and nut from being propelled by the shearing force in an undetermined and unsafe direction.